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Fublistier/Editor; K. D. Cheek, Sr. aka "Dr. RiftonDortis” V1N8: September, 1991 


1 Journal of VHP-UBP Scanner Technology & Engineering 

Published at: COHHtronics Engineering; PQ BOX 262478 : San Diego , CA 92196 Copyright (c) 1991 (All Rights Reserved) 


What do you want first, the bad news or the so-so news? 
Let’s go for the bad stuff, first. It’s common knowledge 
now that the new Realistic PRO-35 is little more than a 
relabeled BC-100XLT. The PRO-35 CPU has some changes in 
its hard programming and there are cosmetic differences 
but the PRO-35 is still a BC-100XLT in disguise. Nothing 
to rant and rave about there and no reason to run out and 
buy one, either. In case someone offers you a PRO-35 for 
free the main differences between it and a BC-100XLT are: 
Any channel can be Priority; one “Monitor" channel is for 
temporary storage of a freq found in the SEARCH mode; has 
both UP and DOWN SEARCH keys; battery pack can be charged 
separately from the scanner which can also operate from a 
separate power supply; has a BEEP function; has the full 
AIRCRAFT BAND of 108-136 MHz. That’s about all worthy of 
mention on the PRO-35 except its hefty price tag of $230, 
while the BC-100XLT is about $40 less. 

The news on the coming PRO-37 is a little better since it 
remains a PRO-34 with apparently all functions and specs 
intact. The PRO-37 is much faster than the PRO-34 at 26 
ch/sec, otherwise it’s the same radio. The increase of 
speed is due to a faster CPU along with a faster Clock 
Oscillator. The rest of the circuit should be about the 
same, including cellular restoration potential, but we’ll 
have to wait and see for sure on that one. Not sure yet. 
Release of the PRO-37 should be in mid-September. 


This is a little better than hearsay, but no confirmation 

yet that a House Subcommittee is preparing a bill to 

direct the FCC to forbid importation or manufacture of 
any radio with capability to receive the cellular bands. 
This bill will also forbid convenient & easy restoration 
capability in the scanner. This could apply to the likes 
of the PRO-2004/5/6/2022/34 and BC-200/760/950/800XLT in 
which the deliberately blocked CMT bands are readily 
restorable. The bill appears to be at the behest of the 
Cellular Mobile Telephone Industry and there is rumored 
to be a clause in the bill which would keep the ban in 
effect until if and w hen the Cellular Industry no longer 
objects to CMT-capable scanners & radios'. John Dingell’s 
name has been associated with the committee that’s 
preparing this bit of invasive legislation. You may want 
to investigate because if government is allowed to 
legislate this sort of horse-manure, then there’s no way 
to stop it from dictating what else we can and can’t have 
in the way of receiving equipment. Time was when only 
transmitters & transmissions were regulated. Tradition 
long had it that the Right of the People to detect and 
receive the air waves was not to be infringed. Tradition 


was weakened with the ECPA of 1986 and now look what’s 
coming down! Iron-Curtain Europe, Asia & other oppressed 
peoples have long been proscribed from possessing certain 
kinds of receivers. Maybe NOW is the time to plan your 
monitoring post for the years to come! Today’s equipment 
might eclipse that of tomorrow’s in utility and value! 

Figure there’s a couple of million of us scannists in a 
nation of 250-million, so as this legislation progresses 
through channels, there will be 248-million people who 
don’t care one way or another; and 1,750,000 of the rest 
of us won’t have heard about what’s going on until it’s 
too late. The quarter of a million of us left will be 
quite impotent to do anything about it. Look at it this 
way: s’pose you heard that knitting needles and anchovies 
were going to be banned. Would you care or be overly 
concerned? Probably not. That’s the way most of America 
will be as the Right to Receive is ground into mincemeat. 
Oh, I forgot — there never was any such right in the 

first place If you want to know where I stand on 

this and related matters, here ’tis: 

They can have my guns, my radios and my computer keyboard 
only after they pry ’em loose from my cold, dead fingers 
but they can have my pork chop & corn bread from 
yesterday’s dinner absolutely for free /be 


We need new subscribers and I have exhausted all known 
avenues of publicity and advertising. I’m open to new 
ideas and suggestions for how the circulation of the 
‘UORLD SCANNER REPORT' can be increased. Your input will 
be welcomed. There is something you can do, anyway: 
please tell your friends, associates and fellow hobbyists 
about us! I’ve long leaned on the values of good will 
and word of mouth. If you like the ‘USR‘ , tell others. 
The rest will take care of itself. We’re doing pretty 
good on growth as it is, but this next year is critical 
as to offering any guarantees of survival for the coming 
years. We need to do very well over the next twelve 
months to carve out a niche. The modifications and 
technology to be developed and the material to write up 
is there; now where are the Readers and the Hackers? 



Check out the new 1992 Radio Shack Catalog which just hit 
the stores! Lots of new goodies including an excellent 
amplified speaker, #21-541, on page 67. What a novel 
product, except that it is almost a carbon copy of 
on pages 71-73! Gosh, I’m not so conceited as to think 

great big Radio Shack copied the design from little ol’ 
me, but sure as tootin’, it’s a monstrous coincidence! 
No matter whether the sorry rascals copied my design or 
not, that new amplified speaker is a heck of a good deal 
for handheld scanners and other audio environments where 
the volume just isn’t up to snuff. The price is a decent 
$23.95. The basic unamplified speaker, tt21-549, costs 
$13.95 and about $10 more is needed to make your own from 
my Project #2 anyway, and which might not end up as good, 
so put #21-541 on your budget if you need general purpose 
audio amplification. 

The new PRO-37 handheld scanner appears to be a clone of 
the PRO-34, and while I haven’t examined the schematics 
yet, I’ll venture the educated guess that the primary 
difference between it and the PRO-34 is a faster CPU and 
Clock Resonator. This was, as you will recall, the main 
difference between the PRO-2006 and the earlier PRO-2005. 
So in essence, owners of the PRO-34 need only change CX-1 
to something around 7 MHz to achieve near parity with the 
new PRO-37. An inherent problem of this method is that 
the DELAY function will decrease by the same proportion 
as the speed increase, so to achieve full parity, you’ll 
need to replace the PRO-34 ’s CPU with one for the PRO-37 
as well as the Clock Resonator. I have proven this to be 
a viable upgrade for the PRO-2005 and it’s probable that 
it will work for the PRO-34 as well. By next issue, I 
will have reviewed the schematics and will give you a 
full report at that time. 

A couple of new base scanners are in the 1992 catalog, 
the PRO-59 and the PRO-58, but these are low-end entry 
level models not worthy of further mention here. In 
addition to the new PRO-37 and PRO-35, there are other 
new handhelds, the PRO-42 and PRO-41. Neither of these 
merit close attention, though if someone were to give you 
a PRO-42, it might make for a useful third-string backup 
to your backup handheld scanner. Nothing more. Bottom 
line is that only three scanner from Radio Shack are 
serious enough to capture your interest: PRO-2006; 
PRO-2022 and the PRO-37. PRO-34 ’s are on clearance sale. 

The new DX-390 Shortwave Portable Receiver heads page 51 
just above the proven DX-440. The DX-390 doesn’t appear 
to have all that much more than the DX-440, but with a 45 
channel programmable memory, it costs $40 more than the 
DX-440. Might be worth a look at $239.95. Looks like 
the DX-440, same as the Sangean TS-803A, is here to stay 
for another year at $199.95. 

LAST CALL - - UORDS TO THE UISE: Discontinued for 1992 
are Radio Shack’s double-shielded 25-conductor and 
9-conductor computer LAN cables, #278-776 & 278-775. Pity 
because these cables contain the finest hookup wires you 
ever used in all your natural-born days. The brighter 
side is that they’re on sale at over 50% off, so stock 
up! Radio Shack’s regular spooled hookup wire isn’t 
worth the powder to blow it to Kingdom Come. The 
insulation drips off like candle wax when the wire is 
soldered and it’s not as flexible and workable as the 
wires salvaged from the above computer cables. This 

computer wire is ESSENTIAL for long term reliability and 

success with my Memory Modifications including the one 
that’s introduced in the next column! 

6.400 CHANNELS FOR THE BC-760/95O/59Q/600 & R-160Q 

My exhilaration over the 6,400-Channel Extended Memory 
Modification (MOD-16 in Vol-1 of the SCANNER MODIFICATION 
HANDBOOK) had hardly subsided before I got to wondering 
if even more were possible. Right away I learned that 
two or more static RAM chips can be stacked with the CE 
(Chip Enable) pins on a switch. (See last month’s 
'Modest Memory Upgrade' article.) That approach to 
doubling the 6,400-Channel Mod didn’t turn me on because 
extra switching and space were required, not to mention 
almost double the work and cost to double the channels. 
And, shucks, if 6,400 channels weren’t enough, then that 
would be like saying that a Rolls Royce isn’t good 
enough. So I didn’t get serious over that idea. But 
later I discovered that the 6,400-Channel Mod wasn’t good 
enough in another area; the number of Blocks! 

Aw sure, if you’re used to one Block of 400 channels in a 
stock PRO-2004/5/6 and suddenly find yourself basking in 
the sheer luxury of 16-Blocks of 400-channels each, you 
might reasonably figure THAT will be good enough for a 
long time. Add it up: suppose you allocate the Home 

Block 00 and Block 01 for general operations. Then 
allocate another couple of Blocks for the Fed Gov’t; one 
each for Local Gov’t; Fire, Medical; Aero; Military Aero; 
Other Military; Transportation; Marine; Ham; CB/Freeband; 
Cordless & IMTS Phones; Broadcast & Media; Sports; Space; 
special events; a couple of Blocks for misc & scratch pad 
operations; and 2 or 3 Blocks for SEARCH & STORE ops, and 

...oops we’ve used up all sixteen Blocks even though 

we’re not close to filling all 6,400 channels! Even the 
Mighty 6,400-Channel Mod can stunt your growth if you are 
sedate about maximum utilization and organization of the 
scanning & monitoring process. This scenario is a bit 
worse for the PRO-2022/2021/32/34 where you still get 16 
Blocks but only 200-channels per Block; and worse still 
for the BC-590/600/760/950 & R-1600 where you still get 
sixteen Blocks but only 100-channels per Block. So I had 
to get serious about memory expansion again because I had 
run out of Blocks and organization space. 

The 6,400-Channel Extended Memory (3,200 Channels for 
200-ch scanners and 1,600 Channels for 100-ch scanners) 
calls for a 32k x 8 (256k) static RAM chip to replace the 
scanner’s stock 2k x 8 (16k) SRAM. You can thus see how 
the mod multiplies the stock capacity by 16. The stock 
SRAM chip has 11 binary address lines (A0 - A10) which 
means the number of addresses is 2 11 or 2,048 (2k), and 
each address hold an 8-bit "word" or code, so 2,048 x 8 
bits = 16,384 bits (16k). The 256k memory expansion chip 
for MODs-16/19/37 has 15 address lines (A0 - A14) for 2 15 
or 32,768 x 8 = 262,144 bits. The only “glitch" about 

"THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 2 

this mod is actually one of its strong points in that the 
CPU addresses only 2 11 registers, so by adding 4 
switches, either DIP as in MOO-16/19/37 or electronic as 
in MOD-28, we have 2 4 (16) manual combos that can be 
addressed by the CPU; hence the 16 Blocks of 400, 200 or 
100 channels, depending on your scanner. 

Heck, 6,400 channels was plenty and would have stayed 
plenty if I could have figured out how to get more Blocks 
and Banks with fewer channels in each. Unfortunately THAT 
aspect is governed by the CPU, the mysteries of which are 
still elusive and unbreakable. It wasn’t a greater number 
of channels that I needed; rather, more Banks & Blocks 
with a minimum of extra complexity, cost, effort & space. 
Well, I found it in spades with a bonus of up to 25,600 
channels for the PRO-2004/5/6; 12,800 channels for the 
PRO-2021/2022/32/34 and a “measly" 6,400 channels for the 
BC-590/600/760/950XLT and the Regency R-1600! But again 
now, the emphasis isn’t on the number of channels if you 
have two or three thousand. Instead, it’s the number of 
Banks & Blocks that’s most important. By now, you’ve 
probably figured out that my 25,600-Channel Mod offers 64 
(sixty-four) Blocks! (2 6 ) In effect, this is like having 
64 scanners lined up side by side, with the only 
limitation being that one at a time can be used. Big 
deal. Well, 64 Blocks of 400, 200, or 100 channels is a 
BIG DEAL, and it is no more difficult to add to your 
scanner than any of my MODS-16/19/37 . Here is what you 
face if you’re interested so far: 

Starting from scratch, the work is about equal to that of 
MODs 16/19/37. Cost will be slightly more since the new 
1-Meg SRAM chip costs about $35-$50, depending on where 
you get it. Parts count increases only slightly to 
negligible, depending on the switching method selected, 
either the manual DIP switch or MOD-28, Keyboard Memory 
Block Controller (KMBC). Here are the differences of 
this mod from MODs-16/19/37 in my books: 

1. The new 1-Meg SRAM chip & Extended Memory Board (EMB) 
that you build will have 32-pins instead of 28, but 
the same number of wires (24) still go to the scanner 
and only two more address wires are needed, (6 total) 
either for the manual DIP Switch or the KMBC. Pin 1 
of the 1-Meg SRAM is not connected to anything, and 
Pin 30 has only a 10-k resistor (R-7) to Pin 32, so 
this accounts for the extra pins. 

2. The pinout of the 1-Meg SRAM chip differs from that of 
the 256-k SRAM, so the exact wiring of the EMB to the 
scanner’s Logic/CPU Board will differ from that given 
for MODs-16/19/37. See Figure 1 in this issue. 

3. DIP Switch Method: 6-pos DIP Switch and two more 

resistors needed. (R-5 & R-6) 

4. KMBC Method: Two more resistors (R-9 & R-10) & LEDs 
(16 & 32) needed & minor wiring changes of the KMBC 
circuit necessary. See Fig-2 in this issue. 

And that’s it, folks; If you have not done an Extended 

Memory modification yet and are faced with the choice of 
MODs-16/19/37 or this new version, you may as well select 
this one unless the slight extra cost is a factor. 


First, gather what you need. You should have both Vols 1 
& 2 of my SCANNER MODIFICATION HANDBOOKS because lots of 
good tips for assembly and installation are included 
there for which space is not available here. Don’t 
forget the Service Manual for your scanner! Next, you’ll 
need a 1-Meg SRAM chip organized as 131k x 8, though it 
might be called a 128k x 8, of which there are several 
mfgrs & part no’s: 











or -12L or -15L 
or -12L or -15L 
or -12 or -15 

or -70 or -85 

There are probably many sources for the 1-Meg SRAM chip, 
but my favorite, DIGI-KEY, doesn’t seem to carry them yet 
so call EASY TECH at (800) 582-4044 and order their part 
number, 618128LP10, at $32.95. EASY TECH is an up and 
coming supplier, similar to DIGI-KEY so get their catalog 
and compare prices on other items, too. 

Everything else you’ll need is common and is listed in my 
books or in Figs 1 & 2 in this issue. Build the EMB as 
generally described in Vol-1 of the SMH and with specific 
variations as shown in Figs-1, 3 & 4 herein. Select your 
Block Switching scheme and if DIP or toggle switches are 
desired, follow the switch diagram in Fig-1. If you want 
to go for the neater, factory-like KMBC, MOD-28, see 
Vol-2 of my book and Figs 2,5 & 6 herein. The only 
difference in the KMBC here from that in Vol-2 of my book 
is that the grounds are removed from U-3, Pins 11 & 13, 
and wires are connected between U-3, Pins 11 & 13 to U-2, 
Pins 13 & 14. R-9 & R-10 are connected to U-3, Pins 10 & 
12 to drive the two new LEDs. Figs 2 J 5 make this clear. 

KMBC Discussion 

The Keyboard Memory Block Controller is a neat method of 
Block selection which requires no switches! You only 
press two keys on the Keyboard (CLEAR & PRGM) at the same 
time to activate the Block. Sequencer. Other scanner 
functions remain undisturbed! Four LEDs are used with 
MOD-16 to indicate which of the 16 Blocks is selected. 
The KMBC is upgraded here for six LEDs to indicate which 
of the 64 Blocks is selected. Contrary to Vol-2 where I 
suggested that the KMBC & EMB can be built on one board, 
well I suppose they can, but I don’t recommend it now. I 
have had nothing but success with two separate boards, 
and if it ain’t broke, let’s don’t fix it. Besides, two 
small boards install a heck of a lot easier than one 
larger board. As suggested in my books, the EMB and KM8C 
should be installed in the PRO-2004, side by side, on the 
bottom of the chassis, between the power transformer and 
the front panel in the bare chassis space there. For the 

THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 3 

PRO-2005 & 2006, the best and ONLY place to install the 
boards is vertically on the chrome-metal shield of the 
Logic/CPU Board in the front panel. See page 89 in Vol-2 
of my book and the discussion there for how to do it, 
except since writing the book, I prefer to reverse the 
KMBC and EMB from the positions shown and move both 
closer to where the stock memory chip was removed. Both 
the EMB and the KMBC must not standoff from the chrome 
metal shield more than about Vs" , and Vis" is even 
better. This is to keep the boards from touching the 
main receiver board when the front panel is swung back 
into position. I think Figs-2, 5 & 6 will make 
construction and assembly of the KMBC rather 
straight-forward and easy enough. When looking at Figs 5 
& 6, please understand that I built that board expressly 
for this article so that it could be xeroxed with maximum 
clarity. You might find a better way to do the layout 
and wiring if you study the Figures closely. If you’re a 
novice at this sort of thing, then copy my work. When 
the KMBC is completed, be sure to first TEST IT using the 
procedure given in Vol-2, pages 145-147. 

Since this mod offers 64 Blocks of Memory, the speed of 
the KMBC becomes an important factor. I designed the 
KMBC (MOD-28) to plod along at about 2 Blocks per second 
which takes about 8 seconds to go from Block 00 to Block 
15. Not too bad. But at that rate about 32 sec will be 
required to go from Block 00 to Block 63; ungood! So we 
need to speed this baby up by a factor of 4 or so, and 
even though 8 Blocks/sec seems too fast for convenience, 
it really isn’t! You will get used to blazing speed 
after a while and appreciate it. Here is how speed of 
the KMBC can be changed: Instead of C-2 in Fig 2 being 
the "normal" 2.2-uF (2 Blocks/sec), try 1.0-uF for about 

5 Blocks/sec or better, 0.68-uF for about 7 Blocks/sec. 
0.5-uF yields about 8 Blocks/sec. When you want to get 
from a low numbered Block to a high one fast, just press 

6 hold the CLEAR & PRGM keys until the count gets close; 
then release the PRGM key while still holding the CLEAR 
key, just tap the PRGM key to advance one Block at a time 
until you hit the desired one. Easy! 


Little to say here. Figure 1 and MOD-16 in Vol-1 of my 
book are quite self-explanatory. All switches are OFF 
for the "Home Block” position. Resistors Rl-6 can be as 
high as 100-k, if you like, though 56-k is specified. 
The biggest problem with the DIP or Toggle Switching 
methods is WHERE to install the switches. If you use DIP 
Switches, for Pete’s Sake, install a DIP socket so that 
the switch can be removed at times. A 14-pin DIP socket 
can be trimmed to 12 pins for this purpose. The DIP 
socket is best installed in the PRO-2005/6 on the front 
panel vertically between the LCD Display and the MANUAL & 
SCAN keys. You’ll have to remove the Logic/CPU board to 
access the inside of the front panel, but so what? Vol-2 
of my book explains in detail how to do this. If you opt 
for toggle switches you’re more or less on your own here. 
Micromini toggles can be installed in the horizontal 
groove below the LCD Display on the 2005/6 but this area 

is best reserved for my LED S-Meter and LED Center Tuning 
Meter mods. If you don’t want these mods now, you might 
later! Some hackers have installed toggle switches on 
the top case, but this restricts easy removal for future 
modifications & maintenance, so don’t do that. 

In the PRO-2004, the DIP Switch socket can be mounted in 
any of a dozen places on the front panel, so look around 
and pick your poison. Nothing critical. Same for toggle 
switches, though again, I don’t recommend them. 

It’s been so long since I’ve been in a PRO-2022 and a 
PRO-32 that I can’t remember the best places where to 
install things, but the -2022 has loads of space in which 
to work, so there should be few problems. The PRO-32 and 
the PRO-34 will require a metal box to be installed on 
the bottom end of the scanner, typical of the photos in 
Vol-1 of my book for MOD-19. An ideal box is made by 
LMB, Model ttM00. It measures 2V 4 “L x 1V 2 "W x l 3 /o"D 
and is finished in black. The KMBC is not really suited 
for handheld scanners yet, (too large?) so DIP Switching 
is the best approach. The DIP socket can be made to fit 
on the little metal box quite easily. Again, see the 
photos under MOD-19 in Vol-1 of my book. 


I’ve never installed the 6,400-ch or 25 ,600-ch Extended 
memory in the PRO-2021, BC-760/950/590/600 or Regency 
R-1600, though I know this mod will work for them. In 
any event, I can’t offer installation clues for that 
reason. Some of our readers have done multi-thousand 
Extended Memory Mods to the above scanners. If someone 
will write up the results of their experiences, and if 
interest warrants, I’ll be glad to allocate some space in 
the ’WORLD SCANNER REPORT’ for these other scanners. 

How To Determine the Block Numbers 

Easy, if you know binary numbering. Still easy, if you 
don’t. First, set up to the Home Block 00 with all DIP 
Switches OFF or all LEDs OFF. Then program something 
into Channel 1 that ends with XX00.000 to signify Block 
00. In the PRO-2004/5/6, use 1000.000. For the PRO-2022 
/34, use 800.000. For all others, use 400.000. Now 
advance the KMBC so that the first LED comes on, or turn 
on the DIP Switch that’s farthest to the right (#6). Now 
select Channel 1 again but program in XX01.000 to signify 
Block 01. Repeat this process using Table 4-16-4 on page 
141 in Vol-1 of my book, except where it ends at Block 
15, you just keep on going until you reach Block 63 which 
for the PRO-2004/5/6, Channel 1 should be programmed with 
1063.000 (or 863.000 or 463.000, etc). 

Bear with me for a wrap up of the binary system: imagine 
six DIP Switches or six LEDs in a horizontal row numbered 
from left to right with 6 down to 1. The farthest right 
(#1) has a decimal value of 1 if ON and 0 if OFF. All 
have a value of 0 if they’re OFF, but if they are ON, 
then decimal value are: #2 = 2; #3 = 4; #4 = 8; #5 = 16 
and #6 = 32. Add up the values of each ON switch or LED 

"THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 4 

co determine which Block is selected. For example, if 
no’s 6,5,2 & 1 are ON, the value is 32+16+0+0+2+1 = 51. 
This is another way to know which Block you’re in without 
referring to the preprogrammed Channel 1 identifier code. 


1. Using a 32-Pin DIP socket, build the Extended Memory 
Board in accordance with Figure 1, with resistors Rl-6 
if DIP Switching is desired, or without Rl-6 if the 
KMBC is to be used; R-7 is required for either; don’t 
forget C-l. Wires on EMB should be 8" long to start 
with; trimmed to size later. Use perf board; PCB not 
worth it; but stick to the dimensions shown in Figs 3 
& 4. Do not insert 1-Meg SRAM chip at this time. 

2. Build the KMBC or the DIP Switch arrangement. Test 
the KMBC before proceeding. See Vol-2 of my book. 

3. Remove the scanner’s stock 2k x 8 SRAM chip, a 24-pin 
flat pack, surface mount chip. Use care, plenty of 
desoldering wick and low heat. 

4. Mechanically install the EMB and either the KMBC with 
LEDs; or DIP Switch arrangement. 

5. Connect KMBC or DIP Switch wires A thru E to the EMB, 
locations A thru E. (See Figs-1&2). Referring to the 
Service Manual for your scanner, connect KMBC power 
wire to scanner +5 volts, but NOT CPU +5v. You don’t 
want the KMBC drawing "memory power". Use the main 
+5v regulator in the scanner, or add a 7805 or 78L05 
of your own if in doubt or if the scanner doesn’t have 
one. For the PRO- 2004/5/6 , proper +5v power is at the 
output of IC-8. NOTE: the DIP Switch arrangement is 
powered from Pin 32 of the SRAM chip, but don’t power 
the KMBC from that point! That’s CPU +5v! 

6. Solder the wires from the EMB according to Fig-1 to 
the pin pads of where the stock SRAM chip was removed. 
This is the same wiring arrangement for ALL SCANNERS, 
so watch for errors; take it one step at a time, and 
be sure of every connection before going to the next. 

7. Insert the SRAM chip into its socket and proceed with 
checkout & preliminary setups given in Vols 1 & 2 of 
my books. If all is well, you’re on your own into a 
new dimension of scanning. 

If all is not well, I will be delighted to assist you 
with troubleshooting and diagnosis of the problem, either 
by mail if you include a SASE and one loose extra stamp 
with a detailed request, or on-line via several Computer 
BBS services including GEnie’s Radio Roundtable; the 
Shortwave/Scanner Echo of the FidoNet, the CIA BBS, (619) 
273-6339, or the Interface BBS, (619) 297-7733. 

If you are not happy with the referrals to Vols 1 & 2 of 
my books, please understand that I’m referring to nearly 
60-pgs of detail that cannot possibly be reprinted in the 
space available here. If I were to do that, complete 
with all the photos, drawings and Tables, we’d need the 

next six or seven issues in which to do it all and 

THAT, dear readers, would not be fair to YOU nor to those 
who aren’t interested in this mod. Besides, 98% of YOU 
already have my books, so my referring to them is the 
correct thing to do for the benefit of almost everyone. 



" THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 5 

F i gure 

MODs 16A, 19A,26A& 374 

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To Memory IC~pl0 < 

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-> To Memory IC~p22 

-> To Memory lC-p20 
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-> To Memory IC-pl 5 
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-> To Memory IC-pl3 

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'THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 6 

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Bob Scott of Virginia contributes a novel approach to a 
Carrier On Indicator. Refer to my MOD-32, page 182-187 
for the standard approach. Bob’s method appears to be 
more effective and simpler than mine. Other than using a 
chip instead of a transistor, the novel difference is a 
bi-color LED which glows GREEN when no signal comes in 
and RED when the SQUELCH breaks. The shortcoming of this 
method is the lack of a reliable source of bicolor LEDs, 
but maybe you readers know of a place. Connect the INPUT 
of the CD-4049 chip to Pin 13 of IC-2 in the PRO-2004/5/6 
or to the SQUELCH OUTPUT PIN of the NFM chip in most any 
other scanner. (See V1N4 for a guide to the various NFM 
chips and their pinouts for most scanners.) ( 

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* I FD&blteD COLO flS WHTUre AT 

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MOD-30 EVENT COUNTER: Vol-2, Page 169, Step 5= Change 
"directly to IC-3, Pin 1" to "directly to IC-3, Pin 3" . 
Sorry, dunno how that happened. Dumb. 


Announcing Doyle Communications Fall/Uinter 1991 catalog 
of scanner and shortwave frequency directories, ham radio 
books, electronics how-to books; scanner antennas, 900MHz 
converters, amplifiers, and adapters. The latest catalog 
lists almost 100 books including Scanner and Ham Radio/C8 
Modification handbooks, Uniden freq directories, Federal 
and Military frequency directories, TV, VCR, & CD player 
repair books plus many more. Satisfaction guaranteed; if 
not satisfied, undamaged items can be returned within 10 
days for a full refund, less S & H. Personal checks up 
to $50.00; VISA, MC and COD orders (USA only) ok. $1 

catalog, refundable with order. Doyle Communications, 
Route S; Box 19, Lake Pleasant, NY 12108. Please mention 
this magazine when ordering your catalog. Orders, call 
(519 ) 549-5515 10am - 8:30 pm FT; closed NED & SUN. 


If you don’t have the time or capability to install mods 
in your scanner, we can do them for you in a timely, cost 
effective, professional manner. SPECIAL thru 9/30/91: 
We will install the new M0D-16A 25,600-Channel Extended 
Memory with Keyboard Memory Block Controller in your 
PRO-2004/5/6 at the regular price for the 6,400 channel 
MOD-16 ($275 f $12 S&H). Effective 10/1/91 this price 
will be $325 +S&H. Also on SPECIAL thru 9/30/91: the 

12,800-Ch M0D-19A for your PRO-34 at the regular price 
for the 3,200-Ch MOD-19 ($225 * $8 S&H). Effective 
10/1/91, the price will be $265 + S&H. COMMTRONICS 

ENGINEERING; PO Box 262478; S an Diego, CA 92196-2478. 

Kc IS K 13 1Z II ID <1 

CD -NOW 0-4 
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This preamp will enable most any tape recorder to detect 
the sneeze of a housefly at 50-ft; maybe further if no 
other sounds are present to mask it! There are many ways 
to house this simple microphone and one-transistor preamp 
and I’ll leave precisely how to your imagination. Private 
investigators might want to miniaturize while tinkerers 
can fit it into a shoe box. The housing is your choice; 
but build the circuit as shown using precision metal film 
resistors and tantalum capacitors for extremely low noise 
and leakage. The trimmer potentiometer is to control the 
Gain of the preamp for optimum recordings. The models I 
have made will pick up a whisper from across a wide room! 

, s*r +it ieo P L e . r OUTPUT 

elect R eT 

■fSsii 270-090 


"THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 8 



Alan Parlato, NY, tells of an interesting phenomena in 
his PRO-2006, which I verified also in the PRO-2004/5! 


When the PRIORITY feature is off, the normal two-second 
DELAY functions on all channels where it is set. There 
seems to be about a half-second DELAY otherwise. 

When the PRIORITY feature is on, there is an interaction 
that seems to shorten or eliminate the DELAY on all 
channels where the DELAY is set. At first I thought it 
might have something to do with the squelch setting, but 
then I noticed it only happens when the PRIORITY is on. 
When the PRIORITY is off, and in SEARCH mode, the DELAY 
works fine (regardless of squelch setting). When the 
radio is on an active channel and the PRIORITY channel is 
sampled, the squelch closes for a split-second (no 
signal). Now, if there is still a signal on the original 
channel, everything is fine, but, if the signal is gone, 
or if the DELAY timer was counting down when the sample 
occurred, the unit instantly starts to SCAN after the 
PRIORITY sample. The reason I think is because the DELAY 
timer was reset due to the PRIORITY sample. Of course, 
when the radio returns to the original channel, there is 
no signal to restart the DELAY timer, so the SCAN begins. 
The result is, if the PRIORITY sample occurs one-half 
second into the DELAY countdown, the rest of the DELAY is 
“cancelled". I’d appreciate your thoughts! /AP 

EDITOR ’S REPLY ■ This oddity is not documented by Tandy 
so the best we can do is guess at it, but yours appears 
to be an “educated guesstimate" . Obviously, it’s a CPU 
function so there’s little we can do about it. My 
EXTENDED DELAY (MOD-29) minimizes its effects, houever. 
Many thanks for your w ell described finding that has not 
been reported elsewhere of which I am aware! /BC 

INDOOR ANTENNAS: One of our readers, and I forgot WHO, 
(sorry), passes along a tip for an indoor antenna that’s 
superior to the telescoping whip or rubber duckie that 
comes with the scanner. "What’s His Name" says he gets 
good results from the amplified Color Supreme V Indoor TV 
antenna from Radio Shack, #15-830. Sounds like an 
alternative for apartment dwellers and others whose 
landlords won’t permit exterior antennas! If this works, 
then there might be even better alternatives for some 
situations. Radio Shack’s Compact Amplified Antenna, 
#15-1611, if mounted vertically, might be a hot dawg. 
Also to consider for cramped quarters: #15-1607. 

POOR SENSITIVITY IN THE PRQ-2004/5/6? I have seen this 
complaint a few times in various reviews around the rag 
mill. But I wonder. After learning the PRO-2004/5/6 
inside & out I really haven’t found sensitivity 
problemsin any that weren’t the fault of a failed 
component. But something under operator control can ruin 
sensitivity AND restore it. I am almost embarrassed to 
say this because I am guilty of it, too, but check the 
position of the ATTENUATOR switch on the rear panel of 
your PRO-2004 /5/6 periodically'! For the most part, it 
should reside in the "0 dB” position. Sometimes, there 
might be a need to set it to the ”-10 dB" position and 
when you do you’re likely to forget all about it and 
wonder a week later why you can’t hear weaker signals 
like you used to. I have trained myself to routinely 
reach over the back of the set and make sure the ATT 
switch is flipped to the RIGHT (0-dB). Quite often, I 
find it to the LEFT (-10 dB) because I do a lot of WFM 
monitoring where the ATT switch is often required. Read 

enough, the PRO-2004/5/6 is one of the few series of 
scanners to provide Automatic Gain Control to its Front 

"THE WORLD SCANNER REPORT" (c) 1991; V1N7 - August, 1991; Page 9 











Radio Interests? (Put YEARS OF EXPERIENCE in each block that applies) 
VHF-UHF Amateur CB Shortwave Professional 

Scanning? Radio? Radio? Listening? Radio? 


Or Occupation: 

List makes 4 models of your scanners 4 other radio equipment: 

USA RATES: (Canada +10t; Other Foreign +20*-surf or +40%-Air) 

1991 Single copies; your choice: 1 ea $ 4.00 

1991 (1st 6-mos, Jan-June) 5 ea $15.00 

CURRENT SUBSCRIPTIONS, with and without Back Issues (BI) 

1991 (2nd 6-mos; Jul-Dec, w/o BI) 5 ea $15.00 

1991 (1-yr; Jan-Dec, w/BI) 10 ea $25.00 

1991-92 (1-yr; Jul-Jun, w/o BI) 10 ea $25.00 

1991-92 (1.5-yr, Jan-Jun w/BI) 15 ea $35.00 

1991-93 (2-yr Jul-Jun, w/o BI) 20 ea $45.00 

1991-93 (2.5-yr, Jan-Jun w/BI) 25 ea $52.50 


SCANNER MOD HND8K, Vol-1: $17.95 + $3.00 S4H * 

SCANNER MOD HNDBK, Vol-2: $17.95 t $3.00 S4H * 

XCanada $4 S4H; Other Foreign $5 S4H; add extra for Air Mail) 
HOBBY RADIO BUYER’S DIRECTORY (600+ listings) $14.95 ppd 

Describe your technical abilities 4 interests; use reverse as needed. 


Enclose a #10 S.A.S.E. and one loose extra stamp if you want 
hobby info 4 personal reply! Business inquiries exempt. 

End Preamplifier and IF stages. AGC remedies myriads of 
problems including front end overload; desensitization, 
and intermod. For reasons not clear, the AGC function is 
active ONLY in the AM and NFM modes; and not in WFH 1 You 
can see evidence of this by tuning the FM Broadcast Band, 
88-108 MHz, where to get the stronger stations to break 
SQUELCH, the ATT switch must be set to "-10 dB". This 
overcomes "desense" effects. At other times, the FM 
signal might break the SQUELCH but sound very distorted 
and garbled until the ATT switch is flipped to *-10 dB". 
This is "front end overload". No wonder, since FM BC 
stations routinely transmit 100,000 watts ERP and more! 
The strongest NFM public service stations are typically 
300 watts or less. 


If you’re willing to power your PRO-2004/5/6 or certain 
other base scanners from an external source of DC instead 
of AC, there is a super way to get more "real estate" in 
which to install modifications and goodies! First, let’s 
look at alternate power sources. Most scanners have a 
special jack on the rear for 12 VDC power. If so, then 
Radio Shack has a good selection of AC-DC Adaptors which 
will do nicely: 273-1652; 273-1653; 22-127 and 22-120. 
Whatever you select, make sure the AC adaptor or power 
supply is rated for at least 10 volts DC and not more 
than 16 volts DC. The current rating should be at least 
500-ma (0.5-amp). A major benefit of running your scanner 
with external DC will be a 9<d% reduction of heat within 
the scanner by the power transformer. (See V1N5 for a 
full article on this!) Now you guessed it! Remove the 
power transformer for a nice gain of "real estate". 
While you’re at it, remove the A/C power cord; use it for 
something else. The power cord hole can be used for a 
jack or a cable bundle. Except for the bulk of an AC-DC 
Adaptor, there are no ill effects or drawbacks of running 
your scanner on external DC power. Advantages are MUCH 
LESS HEAT; less weight and LOTS MORE ROOM for 
modifications and things! 

PRO-2004 PROBLEMS? Reports have surfaced on weak audio 
or peculiar Logic/Display problems in the PRO-2004. I've 
worked on some and helped others diagnose and cure these 
problems. Seems that a run of PRO-2004 's were not 
properly soldered in the production lines. Trouble began 
right after sale. The factory warranty helped many where 
problems surfaced right away. In other cases, solder 
joints held up for a time before failing. Even today, 
several years after the PRO-2004 production lines closed, 
failures due to defective solder joints still crop up. 
One mode of failure is in the audio section where the 
sound fades in and out. A probable remedy is to resolder 
the plated-thru solder spot that's immediately behind 
CN-3, the internal speaker connector on the main receiver 
board. Apply heat & flow solder into this spot. Voila! 

Some defects are in the digital section where the Display 
blanks out; memory is lost or the CPU locks up without 
apparent cause. This cure is more difficult, but fairly 
certain. Lift the Logic/CPU Board (PC-3) from the chassis 
and flip it over. Anywhere from one to 500 solder joints 
must be resoldered. First, resolder only those that look 
bad. This may or may not get the bad one. If not, mark 
the surface of the board in 1-inch squares and resolder 
all joints in one square. Test the unit. Proceed to the 
next square if not remedied by the first; etc, etc. 

Only some PRO-2004 ' s are susceptible to solder joint 
problems, (not all), and you might be able to tell about 
yours. Remove the cover and look around on the main 
receiver board, noting the greenish-white capacitors 
scattered about. If bare leads of these capacitors are 
exposed, look out! Note if any are cockeyed and not 
squarely installed. Also observe the vicinity of where 
the metal boxes & shields are soldered to the main board. 
Look for the presence of solder resin, a brownish, dirty 
residue. Properly soldered units will not show this 
gunk. If you note either situation, there's a chance 
that your unit can develop problems someday, if not 
already. Mostly patience is needed for the cure! 73/bc 

"THE WORLD SCANNER REPORT" (c) 1991; V1N8 - September, 1991; Page 10 

PO BOX 262478 
SAN DIEGO, CA 92196-2478 


For your PRO-2004/5/6...... 

+ 25,600 Programmable Channels 
+ 64 Blocks of 400-Channels each 
+ 640 Scan Banks 
+ 640 Search Banks 
+ 640 Monitor Channels 
+ 64 Priority Channels 
Also, Super Snoop Listening Device 
New Carrier-On-Indicator 
Tips, Hints, Kinks, News 

V 1N8